Code Style, Automated Refactoring and CI

Use PHP-CS-Fixer or PHP_CodeSniffer to enforce PER Coding Style automatically, Rector to apply automated refactorings and version upgrades (e.g., to PHP 8.3 features), and run tests + static analysis + style checks in CI on every pull request. Cache Composer dependencies, test against the PHP versions you support, and fail fast on cheap checks.

# .github/workflows/ci.yml
name: CI
on: [push, pull_request]
jobs:
  test:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        php: ['8.3', '8.4']
    steps:
      - uses: actions/checkout@v4
      - uses: shivammathur/setup-php@v2
        with:
          php-version: ${{ matrix.php }}
          coverage: none
      - run: composer install --no-progress --prefer-dist
      - run: vendor/bin/php-cs-fixer check --diff
      - run: vendor/bin/phpstan analyse --no-progress
      - run: vendor/bin/phpunit

Common pitfalls

• Mixing formatting changes with logic changes in one PR.
• Running Rector without reviewing its diff.
• Only testing on the newest PHP version while production runs an older one.

Key points

• Automate style; never debate it in reviews
• Rector automates upgrades
• CI: style, static analysis, tests on every PR

Further reading: Rector documentation